BY REV. J. E. TENISON- WOODS, F.L.S. 287 



shaft is a close series of small granulations in very regular lines, 

 at the base there is a smooth area which thickens gradually up 

 to a small very finely milled ring. The basal socket is broadly 

 concave. The whole of the base is surrounded by a close thatch 

 of short flat spines, and a finer row makes a short flat fringe 

 along the poriferous zones. There are no other spines except 

 the very small ones covering the miliaries which are like scales 

 on the wings of lepidoptera. The whole surface has a smooth 

 and velvety appearance. 



The difference of this species from all others is that there are 

 eight primary tubercles, while in P. diibia and impcrialis there 

 are only six, and the number of these, according to Agassiz, is 

 very constant for every age and condition of growth. The 

 spines are entirely different from any described species. The 

 anal system is also quite different in the size of the genital 

 plates, their shape, the shape and size of the madreporiform 

 body, the smallness and position of the openings, the size and 

 disposition of the anal plates, and the whole size, shape, and 

 solidity of the test. 



Found occasionally at Botany Bay, Port Jackson, and along 

 the east coast as far as Moreton Bay. The species has been 

 confounded with PhyUacanthus dubia, Brandt. So firmly do the 

 spines adhere to the test that they are always washed up quite 

 entire, and any attempt to remove the primary spines either 

 breaks them, or tears away the coronal plate to which they are 

 attached. 



Height of adult specimen, 100; diam., 90; width of actinosome, 

 32 ; anal system, 28 ; length of largest primary spine, about 62, 

 width at base, 5, at tip, 2\ ; length of flat secondaries, about 10, 

 width about 2\ } thickness 1 millim. The secondaries are very 

 finely grooved and bevilled at the edge. 



The following is a revised list of all the Echini known to me 

 as occurring on the Australian coast. It will be observed that 



